Assessment of vitamin D supply at different age

Introduction . Carrying out studies on the supply of vitamin D in the Russian population is an important task in order to demonstrate the global nature of the problem of vitamin D deficiency. Objective of  the  study . To conduct a  study of  the  level of  vitamin  D at different age periods and to assess the  relationship of the 25(OH)D supply with the seasons of the year. Materials and methods . The study included 10707 people, 78.8% (n = 2323) women and 21.2% (n = 2266) men, mean age 49.86 ± 21.925 years (Me 56.00). Results . Only 17.1% (n = 1833) of the examined had an adequate level of 25(OH)D, 31.4% (n = 3362) people had an insufficient level of 25 (OH) D, 43.7% (n = 4681) of the examined – a deficiency of 25(OH)D and among 7.8% (n = 831) a severe deficiency of 25(OH)D was revealed. An adequate level of 25(OH)D was found only in the group of children under 3 years of age (mean value 40.55 ng/ml). From 4 to 7 years of age, there is a pronounced 2-fold decrease in the concentration of 25(OH)D in all seasons of the year. A consistently low content of 25(OH)D is observed in the period 8-10 years – 20.91 ng / ml, and in the period 11-18 years – 18.30 ng/ml. The lowest average values of 25(OH)D were found at the age of 11-18 years (18.30 ng/ml) and from 19 to 22 years (19.15 ng/ml), as well as in senile (76 years and above) age (19.05 ng/ml). The lowest median concentration of 25(OH)D is recorded in spring (17.70 ng/ml) and winter (18.80 ng/ml), with a slight positive trend in summer (20.40 ng/ml) and autumn (22.00 ng/ml) season. Conclusions . The optimal level of 25(OH)D was found in every fifth (17.1%) subject, vitamin D deficiency (20.01–30.00 ng/ml) was observed in  every third (3362  people out of  10707  examined, 31.4%), a  moderate calcidiol deficiency is recorded among 4681 people (43.7%), a severe deficiency of 25 (OH) D among the surveyed is 7.8%.